Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/02—Aerobic processes
  • C02F3/08—Aerobic processes using moving contact bodies
  • C02F3/085—Fluidized beds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/006—Regulation methods for biological treatment
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/02—Aerobic processes
  • C02F3/10—Packings; Fillings; Grids
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/06—Controlling or monitoring parameters in water treatment pH
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W10/00—Technologies for wastewater treatment
  • Y02W10/10—Biological treatment of water, waste water, or sewage

Definitions

• the invention relates to the field of biological treatment of liquid effluents. More specifically, the invention relates to the field of biological treatment of effluents containing a high content of dissolved ammoniacal nitrogen nitrogen (N-NH 4 + ).
• effluents come in particular from the food industry, petrochemicals, iron and steel, chemicals, wastewater treatment, waste treatment, etc.
• They can thus consist for example of leachate from landfills from storage of household waste, leachate from intensive animal husbandry, refining effluents, synthesis gas chemistry, ammonia water from coking plants, purges from gas washing workshops blast furnaces, effluents from the washing of smoke and / or gasification of coal, water highly charged with ammonium, generated by the anaerobic treatment of waste water, waste water containing ammonium, treated beforehand for their carbon, liquids from physical, biological, chemical or mixed treatment of sludge from treatment plants or their storage, in particular leachates from heaps of spreading sludge, monitoring digesters, etc.
• the biological methods for treating nitrogen pollution known from the prior art involve two steps: a nitrification step and a denitrification step of the effment.
• the nitrification stage is carried out using a biomass which converts, in the presence of oxygen, the dissolved soluble ammoniacal nitrogen (N-NH 4 + ) into nitrites and nitrates.
• the biomass used in this context consists of autotrophic bacteria, for example Nitrosomonas and Nitrobacter, which use inorganic carbon as a carbon source to develop.
• the denitrification step is carried out using a biomass which transforms the nitrites and nitrates into molecular nitrogen gas.
• These heterotrophic microorganisms which may for example be of the Bacillus, Chromobacterium, Micrococcus, Pseudomonas and Spirilium type, use the oxygen bound to the nitrites and to the nitrates.
• the denitrification step is therefore carried out in anoxia.
• This denitrifying biomass uses the assimilable organic carbon present in the environment as a carbon source.
• the nitrification step is often inhibited by the transformation of ammonium ions into nitrites or by that of nitrite ions into nitrous acid.
• Nitrobacters are the most sensitive organisms. There is therefore an undesirable accumulation of nitrites in the medium which can no longer be transformed into nitrates.
• the steps of nitrification and denitrification can be carried out either in separate reactors, one operating with aeration the other without aeration, or in the same reactor with a sequenced aeration making it possible to spare aeration periods and anoxic periods within the reactor, periods conducive to the implementation of the nitrification and denitrification steps.
• Yet another drawback of using the conventional nitrification / denitrification process for the treatment of effluents highly charged with ammonium consists in the fact that in this case it leads to significant production of sludge. However, in all effluent treatment processes, it is sought to reduce the quantity of sludge produced.
• the object of the present invention is to propose a method or an installation making it possible to solve these various problems.
• an objective of the present invention is to propose a process for treating effluents heavily loaded with dissolved ammonia pollution that is simpler than the conventional nitrification / denitrification process.
• Yet another objective of the present invention is to provide a process leading to the production of little sludge.
• an objective is to propose a method and an installation making it possible to design compact treatment systems.
• the invention relates to a process for the biological treatment of effluents highly charged with dissolved soluble ammoniacal nitrogen (N-NH 4 + ), characterized in that it comprises a step consisting in passing said effluent through a reactor containing a biomass at least partially fixed on a support having a high specific surface greater than or equal to 500 m 2 / m 3 , said biomass being capable of degrading the ammonium contained in the effluent up to the stage of molecular nitrogen gas, said step being carried out with continuous moderate aeration, without stirring and with or without very little external supply of biodegradable carbon and with a minimum of alkaline reagents relative to the amount of ammonium to be treated as indicated below.
• the method according to the invention can be more effectively implemented when the N-NH 4 + / BOD 5 ratio is greater than 2.2, preferably 4.4, which corresponds to a Corg / N-NH ratio. 4 + less than or equal to 0.45, preferably 0.22.
• the invention therefore makes it possible to overcome the need to implement aerobic periods or zones and anoxic periods or zones to treat nitrogen pollution and, a priori surprisingly, allows such treatment with moderate aeration. keep on going.
• the process therefore induces, compared to the conventional process of nitrification / denitrification, substantial savings, both on the oxygen source (saving on the order of 25%) and on the carbon source (saving on the order of 99.5% to 100%).
• Another observed advantage of the process resides in the fact that it allows a very rapid start of the nitrogen treatment, in practice in less than 10 days, which represents a gain of more than a week compared to a conventional treatment. by nitrification / denitrification, as well as a warm-up time of less than a month and a half with an elimination rate of N-NH 4 + of at least 90%.
• Another advantage of the process according to the invention is that it better resists supply shocks. It also leads to the production of little sludge, which saves money on the basins necessary for the production and storage thereof, as well as on everything related to their possible treatment and / or disposal.
• Another advantageous advantage of the process according to the invention also consists in the fact that a higher nitrogen / phosphorus ratio compared to that of a conventional nitrification / denitrification does not harm the microorganisms involved in it.
• these microorganisms it should be noted that they can develop from the effluent itself or be brought in by sowing.
• the method according to the invention can be used:
• the supports used in the context of the process according to the invention may be of mineral, natural organic or synthetic nature.
• materials of mineral origin mention may be made of sand, activated carbon or not, shale, clay, magnetite.
• materials of organic origin mention may be made of polystyrene, polyethylene, polyethylene glycol, polyurethane, nylon, foams. This list is not exhaustive.
• the support used will be chosen from the group consisting of balls, grains, Raschig rings, saddles, partitioned tubes, filaments or threads as well as fibrous materials in general.
• said support consists of threads or filaments linked together and which can, for example, form pompoms such as those forming the subject of French patent FR2681798 published on April 2, 1993.
• the process is carried out at a temperature between 15 ° C and 30 ° C, preferably between 20 ° C and 25 ° C.
• the invention also has the advantage of not requiring, in most cases, heating of the effluent to be treated.
• the method is implemented with a hydraulic retention time of the effluent in said reactor of between 0.3 and 2 days, preferably between 1 and 1.5 days.
• the continuous aeration is carried out so as to maintain an oxygen level in the effluent present in the reactor less than or equal to 0.7 mg / 1, preferably between 0.3 and 0.7 mg / 1 .
• the method comprises a complementary step of regulating the alkalinity of the effluent which preferably consists in measuring at the inlet of the reactor a parameter representative of the alkalinity of the effluent, preferably the alkalimetric rate complete (TAC) of the effluent and in parallel the measurement of ammonium, if necessary, to add at least one alkaline reagent to the effluent, if the value of said parameter representative of the measured alkalinity is less than a threshold predetermined.
• TAC alkalimetric rate complete
• the process also includes a step of measuring the pH of the effluent which may be located, preferably in the reactor, as well as a step consisting in triggering an alarm when the parameters representative of the alkalinity and / or of the pH of the effluent exceed or are below a predetermined value and / or out of a range of predetermined values.
• the invention also relates to a device for implementing such a method comprising a reactor provided with means for supplying the effluent to be treated, supports accommodating a biomass, means of continuous aeration, means of evacuating sludge and means of evacuating the treated effluent, characterized in that it comprises means for measuring and rectifying the alkalinity of the effluent entering said device.
• said means for rectifying the alkalinity include means for measuring a parameter representative of the alkalinity of the effluent, preferably the TAC thereof, and for measuring the ammonium parameter, as well as means for 'contribution of at least one alkaline reagent to the effluent.
• the device also comprises means for measuring and controlling the pH of the effluent, preferably in the reactor.
• the device comprises alarm means capable of being triggered when the parameters representative of the alkalinity and / or of the pH of the effluent exceed or are below a predetermined value and / or come out of a range of predetermined values.
• the device includes a reactor 1 provided with means 2 for supplying the effluent to be treated, supports 3 receiving a biomass which is in the form supported by pompons of filaments, continuous aeration means 4 , means for discharging the sludge 5 and means for discharging the treated effluent 6.
• this method comprises means for rectifying the alkalinity of the effluent entering said device including means 7 for measuring the TAC and ammonium in the effluent and means 8 for supplying alkaline reagent to it
• the device also includes means 9 for measuring the pH of the effluent in the reactor.
• the method according to the invention was implemented using this device with effluents of two types under the conditions set out in Table 1 below.
• the effluent used had the average composition, or the ranges of values, according to Table 2 below:

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Biodiversity & Conservation Biology (AREA)
• Microbiology (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Molecular Biology (AREA)
• Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
• Activated Sludge Processes (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Cites Families (5)

• 2001
  • 2001-12-21 FR FR0116776A patent/FR2833940B1/fr not_active Expired - Fee Related
• 2002
  • 2002-12-19 AU AU2002364331A patent/AU2002364331A1/en not_active Abandoned
  • 2002-12-19 EP EP02799105A patent/EP1456136A1/de not_active Withdrawn
  • 2002-12-19 WO PCT/FR2002/004475 patent/WO2003053867A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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